Colorado & Southern #21

Does anyone know the location of the attached photo of Colorado & Southern loco #21 and some history on the loco? I picked this old cabinet photo up on Ebay several years ago.Nothing was written on the back of the photo as to the location or the year/date the photo was taken wich seems to be the norm for old photo's as very few have info on them.I can make out the Colorado & Southern on the tender with a magnifying glass but as for the depot to the right,the only sign that can be seen is the Western Union Telegraph & Cable Office sign.

I'm new to this forum and also a RR engineer.I was able to live in Colorado for about 6 months back in 84/85.I loved it out there,but unfortunately my wife did not like being away from her family.I have some fond memories of riding the Durango & Silverton RR on some family vacations to Colorado while growing up.As for working for a RR i wish i could have done so 100 years earlier!I've also alway's liked RR history and like collecting some of the old photo's of the engines and crews as they are just about all that's left for one to get a glimpse of the past.I also enjoy metal detecting for old railroad iron along abandoned RR grades.There's alot of history out there and much to learn from what was left behind wich is now burried.